Large-scale local-density-approximation band gap-corrected GaAsN calculations

The electronic structure of a GaAsN alloy is calculated using a 4096 atom s upercell, with a 70 Ry plane wave basis cutoff and Ga atom 3d electrons as valence electrons. The charge density of this supercell is generated by pat ching the charge density of a small unit cell with the charge density of bu lk GaAs. The local-density-approximation band gap error is corrected by mod ifying the nonlocal pseudopotentials. A localized nitrogen state [a(1)(N)] is obtained,and it plays an important role in the band gap reduction of GaA sN. (C) 2001 American Institute of Physics.